This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The overall goal of this proposed study is to characterize the role of monocytes as 'Trojan Horse'for viral brain entry in an animal model for acquired immunodeficiency virus syndrome (AIDS). The specific objective is to examine possible altered bone marrow functions and monocyte output during acute infection and how monocytes, once emerged into the peripheral blood pool, migrate onward into the Central Nervous System. Defining the characteristics of newly released monocytes in the peripheral blood pool and their capacity for early brain infiltration could lead to novel drug targeting and treatment options that inhibit acute and chronic neuroinflammation by targeting specific monocyte subsets or their migratory signals.